EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THE POSSIBILITY FOR INCREASING WIND TURBINE EFFICIENCY BY NEW ROTOR HUB DESIGN

Abstract

The aerodynamic performance of a wind turbine heavily depends on the blade airfoil designs, therefore the initial strategy for enhancing efficiency involves using multiple airfoils with varied geometries in blade construction. Building on this, a more innovative approach introduces new geometries for turbine hubs, allowing de-signers to retain the primary blade shape and dimensions during the design process. This process leverages theoretical aerodynamic principles, mathematical models and data from turbine operation under wind flow conditions. The numer-ical model, originally developed with various airfoils, is validated by comparison with experimental results, confirming its reliability. The unsteady airflow model reveals changes in wind turbine efficiency and aerodynamic coefficients at varying angles of attackof the blades. The next phase includes experimental testing of a wind turbine scaled physical model with a newly designed hubwith a hemispherical shape. The 3D-printed model allows for testing at different angles of attack, enabling comparability between numerical and experimental outcomes. Adjusting the position of the hemispherical hub in relation to the blade root provides insights into its effect on wind capture. This method highlights the differences between a conventional turbine hub and an unconventional hemispherical hub, utilizing the same blade configuration. The first approach is implemented in software for airfoil design and analysis, while the second method is employed in software for designing structural elements of the whole turbine